Transfer mechanism for furnaces



Nov. 21, 1933. H. J. KUHLMAN n 1,936,239

TRANSFER MCHANISM FOR FURNACES ATTORNEY.

Nov. 2l, 1933. H. J. KUHLMAN TRANSFER MECHANISM FOR FURNACES Filed May 19, 1932 3 Sheecs-Sheel 2 INVENTOR. /@fey f/fu/,u /mw ATTORNEY.

the first furnace to Patented Nov. 21, 1933 UNITED STATES" 1,936,239 Y'IIRANSFER lmtcnixNIsM Fon'FUaNAcEs Harry J. Kuhlman,

Detroit, ,Mich., assignor to Holcroft and Company, Detroit,l Mich.,y a cor# f poration of Michigan yimplicationMay 19, 1932. vseriai No. 612,293

7 Claims. (o1. 2763-6) This invention relates to transfer mechanism' for usewith -a heat treating furnace orthel like. In heat treating crank shafts or other articles of similar nature itis usually customaryto Ipush the cranks through to a relatively high degree of temperaturethen quench the cranks in a bath of oil and then push the cranks through another furnace in which the temperature is considerablylower than that of therebygive the proper qualities to the metal. furnace positioned above the other in order to conserve'floorwspace so that-itisfnecessary'to lift the 4articles being heat treated from the end of the lower furnace'to the adjacent end of the upper furnace and Vinasmuch as some of these articles are extremely heavy it requires the serv! ices of two men to perform this'transfer operation.

.T t is therefore an object of this invention to provide a transfer mechanism that is practically automatic in operation and which will lift articles from the lower furnace to the upper furnace and whichwill automatically move Vthe articles throughthe upper furnace.v

Another object of the invention resides in the provision of a transfer mechanism which will` keep the carriers on which the articlesto be heat treated are positioned moving in an endlessy line through both the upper and the lower furnaces' thereby preventing cooling of thecarriersand consequent saving of heat units in the furnace.`

Anotherobject of the invention residesfin the combination of pusher and elevator means for maintaining a continuous movement of articles to be heat treated through the heating'compart-- ments.

A still further object rof the invention resides in the provision of compartment and elevatory means for raising the cles in a continuous line therethrough to the 'unloading end thereof, and elevator means'at the` for lowering the .carriersv end ofthe upper heatingv unloading end thereof from the unloading compartment to the heating compartment.V

loading endofthe ylower Another object of the invention-residesin-'the provision of means for quicklyv and automatically withdrawing the heat treated article and carrier block therefor whichis closest to the unloading end ofthe lower furnace to the elevator thereby preventing cooling of the heatedarticle which" would occurv if the article were withdrawn from the furnace at the same-rate of speed--`at which'v tional shape and` are inflongitudinal alignmem:V

it travels through-the furnace;

a furnace and heat thel samenv It is also usual to have -onepusher means positioned at one end of the lower furnace for continuously moving the articles through the lower heating- VThese objects and the several novel-'featuresV of the invention are hereinafter more fully described and claimed and the preferred-form of construction by which lthese objects are' attained is shown in 'the accompanying 'drawings' inl which- Y y Fig: 1 is a sectional view lthroughv af'furnaceV equipped with my improved nism. y

Fig. 2-is a section taken on line 2-2 of Fig..1.-

Fig. 3 Yis a section taken on line 3-3 of Fig. 1.

Fig. 4 is a section taken on line 4.--4 of Fig. 3.

Fig. 5 is an enlarged detail sectional View of aY pair of-guide rails,A carriers Aand crank shaft;

Fig. 6is a section taken online 6-6 of Fig. l.

Fig. *7 is an enlarged detail plan view' ofV the holding pawl.-

Referringrto the drawings',the furnace 1 comprises the -upperheating compartment 2 and the lower heatingk compartment 3 each beingopenV at .their opposite ends as best shown in Fig'. 1 to pertransfer v mecha#- velements (not shown) are Vinstalled in the rey l cesses -6 below therails. The heating compartment 3l has the inwardlygswinging door Tfposi-` 1 tioned adjacent the loading end thereof Hand has the outwardlyswingingdoor 8' positioned adjacentethedischargeend.I If desired similar doors 9 and 10" may beprovided for the" upper heating compartmentZ. A pusher mechanism `8 isV posi?" tioned adjacent the loading end ofthe heating compartment Bland may beof any desired construction for intermittently shoving the carrier blocks 9 through'the-furnace. Y The carriers 9. are designed 'to support a crank shaft l1'V but-it will be understood-that articles of various types may be placed thereon Without departing fromV the spirit of the invention.- By referring to Fig.2,ritwill beseen thatvthere are four 'rails in--eachlheatingcompartment arranged in pairs and that the crankshaft is supported byV th'ercarriers 9 g'uided'in one pair of rails andas'- best shown in Fig.5 .each furnace c'zompartment`V as shown provides for theM advance of two rows*v of work units in para1l`el.- It will be understood that in operation of the pusher mechanism 8that'.

the reciprocating member l0 will move 'the `carri'ers 9;' toward the-heating compartment Sand will' then Amove backto Vthe position shownin Fig. 1 for engaging behind another set of carriers. It willv thus be seen that the entire Vlength of the heating compartments 3 and 2 will be filled with the carriers 9. The ends of the rails 4 stop short ofthe discharge end ofthe heating compartment' 3 and the rail-sections 11 are of similar cross sec,-

positioned adjacent the unloading or dischargtherewith. The sections 11 are each formed with an inturned end 12 for engaging behind the T shapedextension 13 on the member 14 the same having the guide sections 15 suitably secured thereto and in longitudinal alignment with each of the rail sections 1l. The opposite end of the member' 13 is formed with the vertically extending T shaped slot 16 which engages the T shaped extension 17 formed on the cross bar 18 thesame having the racks 19 secured to each end thereof each rack being engaged by a pinion 2G mounted upon a shaft-2l carried in the bearings 22 and rotatable from suitable mechanism (not shown) through the drive pulley 23.

The elevator 24 is formed with the longitudinally extending guides 25 which correctly position the members 14 relatively to the rail sections 11. The elevator 24 is apertured to receive the reducedends 26 of the threaded rods 27 and is further provided with the apertures 28 which slidably engage the guide rods 29. The rods 29 are suitably secured attheir lower ends tothe floor and at their upper ends to the framework extending from the end wall of the furnace. The gears or sprockets 30 threadedly engage the rods 27 and are suitably rotated by a chain or gears (not shown). The supporting bars 31 are secured at their outer ends to the framework 32 the same being .suitably secured to the floor and the bars 'are slidably engaged by the cross bar 18 and extend under the members 14 to support the weight of the same when the cross bar 18 is moved outwardly in the direction of the arrow shown in Fig. 3. Each of the pusher blocks 9 is formed with a notch 32 which is engaged by the beveled pawl 33 secured to the arm 34 the same being pivotally mounted at 35 to the elevator 24. A spring 36 abuts the arm 34 and the opposite end abuts the standard BTthe same also being suitably secured to the elevator 24. A roller 38 is pivotally mounted between the ears 39 extending from the bar 34 and is adapted to engage the vertically extending rail 4o the same having a flared lower end 41, for a purpose to be hereinafter described.

A pusher mechanism 42 is suitably mounted upon the top wall of the furnaceand adjacent thejloading end 0I" the heating compartment 2 andcomprises vthe link 43 pivotally secured to the crank 44 the same being rotated through `suitable mechanism indicated generally at 45. An

arm 46 is pivotally secured to the link 43 and is pivotally secured at 47 to the bracket 48 extending from the end wall of the furnace. The lower end of the arm 46 has one end of the link 49 pivotally secured thereto the opposite end being pivotally secured to the cross bar 50 slidably upon the rods 51 carried by the framework 52 and the end wall of the furnace. An elevator 53 which is similar in construction to the elevator 24 is ing of the heating compartment 2 and is arranged to lower the carriers 9 from the rails 5 in the upper heating compartment 2 to longitudinal alignment with the rails 4 in the lower vheating compartment 3.

The operation of the device is as follows: Assuming that both the upper and lower heating compartments are loaded with the carriers 9 upon `operation of the pushermechanism 8 the carrier v9 on Awhich a crank shaft has been placed will be moved along the rails 4 toward the heating chamber 3 and will consequently move all of the carriers along a predetermined distance and will move the carrier 9 adjacent the unloading end of the heating compartment 3 onto the rail sections 11 f suitable mechanism (not shown) win rotate the pinions 20 and will move the racks 19 in the direction of the arrow shown in Fig. 3 and will vmove the cross bar 18 in the same direction and the cross bar will pull the members 14 and the rail sections 11 also in the same direction until the carrier on the rail sections 11 is positioned over the elevator 24. The pinion gears 20 will then be rotated in the opposite direction and will move the rail sections 11 back to the position shown' in Fig. 1. The pawls 33 will engage in the notches 32 in the carriers 9 which are positioned over the elevator and will preventV return of the samejand inasmuch as the rails 15 of the members 174 align with the-rail sections 11y the same-will engage the flanges of the carriers 9. rIfhe elevator 24 will then be raised by rotating the sprocket 39 and thesame will move upjuntil the rails 15 come in longitudinal alignment with the rails 5 in the upper heating compartment 2. It will be seen therefore that as the elevator -is lifted that the roller 38 will engage the iiared end 41 of the rail 40 and will move the pawl 33 L out cf engagement with the notch 32. n

When the elevator has reached its upper limit of travel the pusher mechanism 42 will come into operation and the pusher head 5G will engage behind the carriers 9 and move the same onto the guide rails in the upper heating compartment 2 and since the carriers are in end to end relation in the upper heating compartment thew one adjacent the discharge or unloading end thereof will be moved onto the elevator 53 and the elevator then lowered. The crank that is on the carrier will then be removed and a new one placed thereon and the pusher mechanism 8 will then be put in operation to perform another cycle of operation as heretofore described.

It willgbe noted that the elevator 24 may be raised and lowered as the T shaped extensions 13 will slide by the inturned ends 12 and the T vshaped grooves 16 will slide by the T shaped extensionsA 17 and when lowered the parts will ya again assume the position shown in Fig. 3 to permit withdrawal of the sections ll from the furnace.

It will be understood, of course,V that the different steps in the operation will be so timed as to be put It will be..

by suitable mechanism (not shown) in operation at the correct instant. further noted that movement of the racks 19 will be relatively rapid so that the carrier on the rail section 11 will be quickly withdrawn j from the furnace to prevent cooling of the heat treated article. It will be understood that any number of rails may be used in the furnace without departing from the spirit of the invention. Y

It is the usual practice in treating crank shafts or the like to quench the cranks in a bath of oil after they are passed through the first heating compartment and prior to putting them through the second heating compartment. This particular step, invention as-the principal object is to keep a continuous line of carriers intermittently moving through the two heating compartments. 1t will be seen that the carriers have very little chance to cool as they are moved from one heating compartment to the other thereby effecting-a required to raise the temperature of the carriers however, forms no part of this to the temperature of the furnace. It will be Lacasse understood, of course, that when the elevator 24 has reached its highest point and the carriers thereon moved into the upper heating compartment that the elevator will immediately lower to a position to receive the next set of carriers from the lower heating compartment and during this downward movement the rollers 38 will pass out of contact with the rail 40 to permit the pawl 33 to be in' position to hold the next carriers 9 that are positioned on the elevator.

From the foregoing description it becomes evident that l' have provided a transfer mechanism for furnaces that is simple and eicient in operation and which will materially reduce the amount of manual labor required in operation of the furnace.

Having. thus fully described utility and modeor" operation, desire to secure by Letters Patent States is Y l. The combination with a furnace having two heating compartments, one positioned above the other, of a plurality of carriers for supporting articles thereon, means in each compartment for guiding the carriers therethrough, means at one end of the lower heating compartment for moving the carriers therethrough, elevating means at the opposite end of the lower heating compartment for raising the carriers to a position in longitudinal alignment with the guide means in the upper heating compartment, and means for moving the carriers from the elevating means through the upper heating compartment and along the guide therein, and means adjacent the opposite end of the upper heating compartment for lowering the carriers to al position in longitudinal alignment with lower heating compartment. Y

2. A transfer echanism for a furnace having an upper and lower heatingcompartment, comprising a movable section positioned in the lower furnace and adjacent theY unloading end thereof, means for moving an article thereon, an elevator positioned adjacent the unloading end of the lower heating compartment, means for raising and lowering the same, means for moving the movable section to a positionr above the elevator, and for returning the movable section to its position in the'furnace, means for holding the article in superimposed relation on the elevator during the return of the movable section, and means adjacent the loading end of the upper heating compartment for moving the articles on the elevator into the upper heating compartment.

3. A transfer mechanism for a furnace having an upper and a lower heating compartment comprising a movable section positioned in the lower furnace and adjacent the unloading end thereof, a plurality of carriers in the upper and lower heating compartments, means for moving one of the carriers onto the movable section, an elevator positioned adjacent the unloading end of the lower heating compartment, means for raising and lowering the saine, means for moving the movable section and the carrier thereon to a position above the elevator, and for returning the movable section to its position in the furnace, and means for holding the carrier in its position above the elevator during the return of the movable section, and means for moving the carrier into the upper heating compartment when the elevator is in its raisedV position.

4. A transfer mechanism for a furnace having an upper and lower 'a heating compartment, comwhat I claim and of the United my invention, its Y the guide means in the` prising a movable guide section positioned in the lower heating compartment and adjacent the unloading end thereof, a plurality of carriers in the upper and lower heating compartments, means for moving one of the carriers onto the movable guide section,

the unloading end of the lower heating compartment and having movable guidel means thereon longitudinally aligned with the movable guide section in the lower heating compartment, means for moving the movable guide section in the furnace and the carrier thereon to a position above the elevator, the said means at the same time moving the guide means on the same, and for returning the movable guide section to its position in the furnace at the same time returning the guide means on the elevator to its position thereon, and means for holding the carrier in its superimposed relationship to the elevator during the return of the guide means to the furnace to permit the carrier to be engaged by the guide means on the elevator, means for raising the elevator'to a position whereby the carrier is aligned withthe upper heating compartment, means for moving the carrier from the guide means on the elevator into the upper heating compartment, said raising means being reversible for returning the elevator to its position whereby the guide means thereoncomes in longitudinal alignment with the movable guide section in said lower compartment.

f 5. The combination with a furnace having two heating compartments, of a plurality of carriers for supporting articles thereon unshielded from the influence of the heat in the compartments, means for causing movement of the carriers through one compartment, means at the discharge end thereof for withdrawing the loaded carrier from the compartment to permit unloading and reloading thereof, means for transferring the carriers to the adjacent end of the companion compartment, and means for causing movement of the said carriers through the second compartment.

6. The combination with a furnace having two heating compartments, of a plurality of carriers for supporting articles thereon unshielded from influence of the heat in the compartments, means for causing movement of the carriers through one compartment, means of for withdrawing the loaded carriers from the compartments to permit unloading and reloading thereof, means for transferring the carriers to the adjacent end of the companion compartment, means for causing movement of the said carriers through the second compartment, and means for returning the carriers to the loading end of the first compartment. ,Y

'7. The combination with a furnace having two vheating compartments, one positioned above the other, of a plurality of carriers for supporting articles thereon, means at one end of the lower heating compartment for moving the carriers therethrough, elevating means at the opposite ends of the lower heating compartment vfor raising the carriers to a position in longitudinal alignment with the upper heating compartment, means for moving the carriers from the elevating means through the upper heating compartment, and means `adjacent the opposite end of the upper heating compartment for lowering the carriers to a position in longitudinal alignment with the lower heating compartment. j

HARRY J. KUHLMAN.

an elevator positioned adjacent the elevator fromy atV the discharge end there- 

